It's their top seller. They gladly admit it. And who are we to doubt such boasts? It's made to order. It's as vividly green as the poison tree frog mugs on those "Save the Rainforest" direct-mail fund-raising pieces. Shove in a chip. The guac is chunky, nutty and fresh. This is stellar stuff with white onion, lime, cilantro and roasted garlic stirred into a bumpy slurry. You can feel the citrus concussion from your cheek membranes all the way down to your hangnails.